benbalter/wordpress-to-jekyll-exporter — pull request #45 by kennethkalmer (2014-12-19 15:18:03+00:00)
Title: Add the post's guid to the extracted frontmatter

Extension of #43, seems the post's GUID's are also instrumental for recreating Disqus identifiers. I suspect GUID's might be useful in other cases too, like where Wordpress used it for feeds.